package com.tcat.common.utils;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.lang.Nullable;

import java.io.IOException;
import java.util.List;
import java.util.Map;


public class JsonUtils {

    public static final ObjectMapper mapper = new ObjectMapper();

    private static final Logger logger = LoggerFactory.getLogger(JsonUtils.class);

    @Nullable
    public static String toString(Object obj) {
        if (obj == null) {
            return null;
        }
        if (obj.getClass() == String.class) {
            return (String) obj;
        }
        try {
            return mapper.writeValueAsString(obj);
        } catch (JsonProcessingException e) {
            logger.error("json序列化出错：" + obj, e);
            return null;
        }
    }

    @Nullable
    public static <T> T toBean(String json, Class<T> tClass) {
        try {
            return mapper.readValue(json, tClass);
        } catch (IOException e) {
            logger.error("json解析出错：" + json, e);
            return null;
        }
    }

    @Nullable
    public static <E> List<E> toList(String json, Class<E> eClass) {
        try {
            return mapper.readValue(json, mapper.getTypeFactory().constructCollectionType(List.class, eClass));
        } catch (IOException e) {
            logger.error("json解析出错：" + json, e);
            return null;
        }
    }

    @Nullable
    public static <K, V> Map<K, V> toMap(String json, Class<K> kClass, Class<V> vClass) {
        try {
            return mapper.readValue(json, mapper.getTypeFactory().constructMapType(Map.class, kClass, vClass));
        } catch (IOException e) {
            logger.error("json解析出错：" + json, e);
            return null;
        }
    }

    @Nullable
    public static <T> T nativeRead(String json, TypeReference<T> type) {
        try {
            return mapper.readValue(json, type);
        } catch (IOException e) {
            logger.error("json解析出错：" + json, e);
            return null;
        }
    }

//    @Data
//    @AllArgsConstructor
//    @NoArgsConstructor
//    static class User{
//        String name;
//        Integer age;
//    }
//
//    public static void main(String[] args) {
//       User user=new User("Jack",21);
//        //toString   序列化   json:{"name":"jack","age":21}
//        String json=toString(user);
//        System.out.println("json:"+json);
    //反序列化   JsonUtils.User(name=jack,age=21)
//         User user1=toBean(json,User.class);
//         System.out.println("user1="+user1);
    //toList    序列化   list=[20,-10,5,15]
    //  String json="[20,-12,5,15]";
    //  List<Integer> list=toList(json,Integer.class);
    //  System.out.println("list="+list);
    //  toMap    map={name=jack,age=21}
    //String json="{\"name\":\"jack\",\"age\":\"21\"}";
    // Map<String,String> map=toMap{json,String.class,String.class};
    //System.out.println("map="+map);
    //  map={name=jack,age=21}
    //  map={name=Rose,age=18}
    //   String json=[{\"name\":\"jack\",\"age\":\"21\"},{\"name\":\"Rose\",\"age\":\"21\"}]
    //   List<Map<String,String>> maps=nativeRead(json,new TypeReference<List<Map<String,String>>>(){
//       });
    //   for(Map<String,String> map:maps){
    //       System.out.println("map="+map);
    //   }
    //
//    }
}
